1. Field of the Invention
The present invention relates to a data processing apparatus used for sales transactions requiring handling of coins.
2. Description of the Related Art
Electronic cash registers have been used to register cash for sold items in a lot of supermarkets. A cashier registers cash for the sold items, calculates a total amount of the sold items, and charges the total amount to a customer. When the customer tenders an amount exceeding the charged total amount, the cashier takes out cash as a difference between the tendered amount and the charged amount from a drawer of the cash register and hands it as change to the customer.
The drawer of the cash register is partitioned into a plurality of cash compartments for respectively storing coins and bills of predetermined denominations so as to allow the cashier to pick up a desired amount of change. In general, although the cashier carefully checks the number and denomination of bills before they are paid back as a change to the customer, coins as the auxiliary currency are not carefully handled as compared with the bills because a total amount of coins as change is not so large in most sales transactions.
For example, when there are a lot of customers who wait in a line to pass through a cashier counter after the cashier stores the cash from one customer into the compartments, she or he must immediately register cash for the next customer. In particular, coins tend to be mixed with coins already stored in the compartments. Even if coins are stored in a wrong compartment, the cashier may not notice it. The coins in the wrong compartment may be paid back to customers as coins which are supposed to be stored in other compartments.
In recent years, various consumption taxes have been introduced to cover various sales transactions, and a charged amount usually includes a fraction corresponding to the consumption tax added to the price of an item. As a result, cashiers are more frequently handling coins as small change, and it is estimated that settlement errors are correspondingly increasing.